java sql将某个字段附为空值 sql设置某个字段可以为null

1.在SQL Server数据库中要把某个字段改null?

         语句：set xxxx=null;

         快捷键：ctrl + 0;

 

2.得到任意一个存储过程的参数列表

方法1:  

select  c.name  from  syscolumns  c,sysobjects  o  

where  o.id=c.id  

and  o.xtype='P'  

and  o.name='your  proc  name'

 
 
方法2:  

exec  sp_procedure_params_rowset  @procedure_name  =  'storeproc  name'

例如：

 1)、

select  c.name,c.colorder  from  syscolumns  c,sysobjects  o  

where  o.id=c.id  

and  o.xtype='P'  

and  o.name='proc_EMS_SearchEquipment'

得到

@type 1
@model 2
@location 3
@description 4

2)、sp_procedure_params_rowset @procedure_name='proc_EMS_SearchEquipment'

DBName dbo proc_EMS_SearchEquipment;1 @RETURN_VALUE 0 4 0 NULL 0 3 NULL NULL 10 NULL NULL int int

DBName dbo proc_EMS_SearchEquipment;1 @type 1 1 0 NULL 1 3 NULL NULL 10 NULL NULL int int

DBName dbo proc_EMS_SearchEquipment;1 @model 2 1 0 NULL 1 129 50 50 NULL NULL NULL varchar varchar

DBName  dbo proc_EMS_SearchEquipment;1 @location 3 1 0 NULL 1 129 50 50 NULL NULL NULL varchar varchar

DBName dbo proc_EMS_SearchEquipment;1 @description 4 1 0 NULL 1 129 100 100 NULL NULL NULL varchar varchar

 3.怎样使用该函数

//执行存储过程
 public DataSet ExecuteDataSet(string storedProcedure, params object[] param)

        {

            SqlCommand selectCommand = this.GenerateCommand(storedProcedure, param);

            selectCommand.CommandTimeout = 300;

            DataSet dataSet = null;

            SqlDataAdapter adapter = new SqlDataAdapter(selectCommand);

            try

            {

                dataSet = new DataSet();

                adapter.Fill(dataSet);

            }

            catch (Exception exception)

            {

                throw exception;

            }

            finally

            {

                if (!this.UnderTran)

                {

                    this.Connect.Close();

                }

            }

            return dataSet;

        } 
//将传入的object[]值赋给对应存储过程参数
 private SqlCommand GenerateCommand(string cmdstr, params object[] val)

        {

            SqlCommand command = new SqlCommand(cmdstr, this.Connect);

            command.CommandType = CommandType.StoredProcedure;

            if (!this.UnderTran && (this.Connect.State != ConnectionState.Open))

            {

                this.Connect.Open();

            }

            else

            {

                command.Transaction = this.Tran;

            }

            if ((val != null) && (val.Length > 0))

            {

                SqlCommand selectCommand = new SqlCommand("sp_procedure_params_rowset", this.Connect);

                if (this.UnderTran)

                {

                    selectCommand.Transaction = this.Tran;

                }

                selectCommand.CommandType = CommandType.StoredProcedure;

                selectCommand.Parameters.Add("@procedure_name", cmdstr);

                DataSet dataSet = new DataSet();

                new SqlDataAdapter(selectCommand).Fill(dataSet);

                DataTable table = dataSet.Tables[0];

                table.Rows.RemoveAt(0);

                for (int i = 0; i < val.Length; i++)

                {

                    if (val[i] != null)

                    {

                        command.Parameters.Add(table.Rows[i]["PARAMETER_NAME"].ToString(), val[i]);

                    }

                }

            }

            return command;

        } 
//调用函数
   public DataTable   SearchEquipment(int type,string model,string location,string description)//OSR.Entity.EMSData  

        {object[] obj = new object[4];

            obj[0] = type;

            obj[1] = model;

            obj[2] = location;

            obj[3] = description;

            return visitor.ExecuteDataSet("proc_EMS_SearchEquipment", obj).Tables[0];

        }